4,455 research outputs found
Trigger, reconstruction and physics performances in LHCb
LHCb is one of the four major experiments that will take data at the LHC, due
to start operation in 2007. The primary aims of LHCb are to perform precision
tests of CP violation and to search for new physics in b hadron decays. About
10^12 bb pairs will be produced in LHCb per 10^7 seconds (a nominal year) in pp
collisions with a luminosity of 2x10^32 cm^-2 s^-1. A large, high-purity sample
of b hadrons, decaying in a variety of channels, will be accumulated. LHCb will
perform a detailed study of B meson mixing, precise measurements of the angles
of the unitary triangle and investigations of rare decays in b hadrons, looking
for new physics in loop-induced processes. The LHCb detector is optimised to
reach these physics goals. Here a brief description of the reconstruction
performance is given, and the sensitivities in typical channels for the study
of Bs mixing, CP violation and rare decays are summarised.Comment: Hadron Collider Physics Symposium (HCP06) Duke University Durham,
North Carolina; May 22-26, 200
Lepton universality tests with leptonic kaon decays
The NA62 experiment at CERN aims to use rare kaon decays to search for new
phenomena beyond the Standard Model. During the current short term phase (data
taking completed in years 2007-8), the ratio of leptonic
decay rates is studied, which tests the structure of weak interactions and
lepton flavour universality. In this paper, the analysis is summarized,
and the preliminary result is discussed, based on 59963 candidates collected in 2007.Comment: Proceedings of CKM2010, the 6th International Workshop on the CKM
Unitarity Triangle, University of Warwick, UK, 6-10 September 201
Production of high quality 11C beams for radiation treatment and accurate PET-CT dose delivery verification
Radiation therapy with external beams of positron emitter light ions offers the
optimal solution for simultaneously treating and in vivo monitoring the delivery of the
dose in 3D with Positron Emission Tomography (PET) or PET-Computed
Tomography (CT) imaging. Specifically, positron emitter light ion beams merge the
main distinctive advantages of light ion therapy, namely a high conformal and
biological effective dose delivery to the tumor, an optimal penumbra, and sparing of
the surrounding normal tissues, with the advantage of a high β+-activity signal mainly
produced directly by the beam itself, and therefore not primarily dependent on the
specific stoichiometry of the body tissues.
The aim of this thesis is to explore a method to maximize the generally low
production yield of 11C ion beams through in-flight fragmentation of a primary 12C
ion beam on a dedicated decelerating target. The thesis provides a practical solution
applicable to cyclotron, synchrotron and linac based hospital facilities. The study
investigates the main steps from the production of the beam and the transport through
the beam optics system to the purification of the beam from other potentially
contaminating fragments. Analytical models of transport of ions in matter, as well as
the Monte Carlo code SHIELD-HIT were used to conduct the analysis.
The proposed beam line includes a composite production target made of a 20 cm
thick liquid hydrogen section followed by a variable thickness section consisting of
plane parallel slabs of polyethylene. The first section is selected to maximize the 11C
ion beam intensity, whereas, the second section is used to reduce the beam energy to
the desired value, maintaining the high 11C ion yield. To be able to minimize the
energy spread of the beam, and the contamination from other fragments, a variable
wedge-shaped degrader and a Time Of Flight (TOF) Radio-Frequency driven velocity
filter are included in the beam line together with dipole and quadrupole magnets.
A 11C ion beam intensity of about 4-6% of the primary 12C ion beam intensity with
radial spot size confined to 0.5 cm in radius, and an energy and angular spread of
about 1% and 1°, respectively, are achievable. The 11C ion beam purity is expected to
be about 99%. The proposed system for production of high quality 11C ion beams
contributes to the developments of an accurate PET-CT based dose delivery
verification, ultimately aiming towards a biologically optimized adaptive radiation
therapy
Kaon experiments at CERN: NA48 and NA62
Searches for violation of lepton flavour universality and lepton number
conservation in kaon decays by the NA62 and NA48/2 experiments at CERN, status
and future plans of the CERN kaon programme are presented. A precision
measurement of the helicity-suppressed ratio of the
and decay rates has been performed using the full data set
collected by the NA62 experiment in 2007--2008. The result is
, in agreement with the Standard Model
expectation. An improved upper limit on the rate of the lepton number violating
decay from the NA48/2 experiment (2003--2004
data set) is presented. Finally, the NA62 project aiming at a measurement of
the branching ratio of the ultra-rare decay at 10%
precision is discussed.Comment: Talk given at PhiPsi 2011 conference (Novosibirsk, Russia, September
2011). To be published in Nucl.Phys.B Proc.Sup
Energy networks in sustainable cities: towards a lull integration of renewable systems in urban area
The European Commission is supporting many
projects intended to improve the use of renewable energy
sources and a special attention has been devoted to the case of
large scale urban areas. The project POLYCITY represents a
significant demonstration of this energy policy which is applied
to 3 cities: Barcelona, Stuttgart and Torino. The case of Torino
appears of particular relevance because it is dedicated to the
improvement of existing building and installations which is in
our opinion the most frequent situation. In particular the most
qualifying characteristic of Torino project is the installation of a
new combined heat and power generator (CHP) coupled with
the existing district heating and an absorption chiller in order to
supply energy more efficiently in a district which include the
Housing Authority of the Province of Torino (ATC) and 30
council buildings. The paper describes this project highlighting
the use of renewable sources and the initial results. The
preliminary assessment of our experiment will be discussed
according to socio-economic, environmental and energetic
indicators
Perceptions and imaginaries about the fourth industrial revolution between geographies of opportunity and discontent: Some reflections on the Italian case
The pervasiveness of advanced technologies and their disruptive impact on society have spurred the debate on the emergence of a new industrial revolution and on its positive and negative effects, both at an individual and spatial level. This paper aims to contribute to this debate, focusing attention on the perception of changes related to the Fourth Industrial Revolution and exploring new methods of analysis of the manifestations of both techno-enthusiasm and opposition to it. Starting from the extensive literature in this field, the work adopts two research perspectives: the study of imaginaries and narratives developed around the Fourth Industrial Revolution, which convey different messages from social groups and places; the geographies of opportunity and discontent, which address the resentment expressed by some localities towards advanced technological models and growing inequalities. In this work the Fourth Industrial Revolution is not interpreted through data about the technological variables or interviews to protagonists of the phenomenon; rather, emphasis is on the points of view of non-institutional subjects and, in particular, the opinions expressed by people on the Web. For this reason, the sentiment analysis has been adopted to identify both positive and negative polarities and the relevance of specific feelings through the selection of key words related to the notion of the Fourth Industrial Revolution. The empirical analysis based on this methodology focuses on the Italian case in a specific period (first and second phase of the pandemic, from January 2020 to September 2021) and, at a local level, on the comparison between four medium-sized cities (Pisa, Lecce, Taranto and Terni). This paper also tries to extend recent contributions through the provision of new perspectives for the definition of policies designed with the involvement of the population and places regarding both the processes of technological change and the definition of new socio-spatial models
EXPERIMENTAL INVESTIGATION OF A DISK-SHAPED REENTRY CONFIGURATION AT TRANSONIC AND LOW SUPERSONIC SPEEDS
Disk shaped reentry body at transonic and low supersonic speed
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